1. Field of the Invention
The present invention relates to a map editing device, more particularly, to a map editing apparatus which assists to update a three-dimensional digital map of an area by utilizing images obtained by imaging the area.
2. Description of the Related Art
JP-A-60-95474 discloses a prior art technology entitled "GENERATION METHOD OF PREMISE MANAGEMENT DIAGRAM" which collates an aerial photograph of an area with a map (two-dimensional map) of the area and detects object shapes not coincident between them.
JP-A-3-196372 discloses a technology entitled "POSITIONING APPARATUS OF IMAGES" which effects coordinates transformation for a two-dimensional numerical value map comprising (X, Y) coordinate lines to generate a perspective projection map, and collates the map with images.
JP-A-5-181411 discloses a technology entitled "MAP INFORMATION COLLATION/UPDATING METHOD" which effects coordinates transformation for a three-dimensional numerical value map comprising (X, Y, Z) coordinate lines to generate a perspective projection map, collates this map with an aerial photograph and updates map information by information regarding objects in the aerial photograph images when collation of the objects in the perspective projection map with the objects in the aerial photograph images proves successful.
According to the prior art technology described in JP-A-60-95474 described above, the aerial photograph and the map are superposed and collated with each other. However, the aerial photograph is based on the perspective projection whereas the map is based on the orthographic projection, and deviation resulting from these projection methods is unavoidable, and detection accuracy is low. Further, because the two-dimensional map does not have information of the object's altitude, there remains the problem that the virtual change of the object cannot be detected.
The prior art technology of JP-A-3-196372 involves the problem that because the two-dimensional digital map comprising the (X, Y) coordinate lines does not have information regarding the object's altitude, the technology cannot detect the virtual change of the object.
Though the technology described in JP-A-5-181411 can detect the change of the objects inclusive of the virtual change, there remains the problem that the map information can be updated only by a manual operation if collation between the object in the perspective projection map and the object in the aerial photograph image proves unsuccessful. (When a building is lost or is built afresh, for example, the map information cannot be updated automatically).
All these prior art technologies do not at all consider means for supplementing insufficient information, means for making it easy to re-measure an object that has changed, means for making it easy to determine an area in which a lot of changes of objects have occurred, and so forth.